Numerous insects live in forests as a component of forest ecosystem. Forest insect pests are defined certain insects when they adversely affect ecological, economic, and social values that we associate with forest. Kinds of forest insect pests are continually changed as a result of change of forest ecosystem and the introduction of foreign alien insect pests. Forest pest management is the maintenance of destructive insects at tolerable levels by the planned use of a variety of preventive, suppressive, or regulatory tactics and strategies that are ecologically and economically efficient and socially acceptable. However, the system of forest pest management is slighly different according to the nation and case of insect pests. Currently, the most important insect pests of Korea are Monochamus beetles and Platypus koroensis, which are insect vectors of pine wilt disease and oak wilt disease, respectively. Major forest insect pests are Thecodiplosis japonensis, a gall maker of pine needle and sapsucking insects such as black pine bast scale, Matsucoccus thunbergianae, Corythucha ciliata, Lycorma delicatula. Defoliating insects, such as Dendrolimus spectabilis, Hyphantria cunea, Agelastica coerulea, Acantholyda parki, and phloem boring insects, such as Tomicus piniperda and Ips bark beetles are also regarded as major forest insect pests. Management of forest insect pests are different from kinds of insect species. Control methods currently used are as follows; (a) Chemical control : ground and aerial spray of low-toxicity insecticide, trunk injection of systemic insecticide, fumigation, etc. (b) Biological control : release of parasitic wasps, use of Beauveria bassiana. etc. (c) Physical or mechamical control : burn, crush, etc. (d) Silvicultural practice : salvage cutting, clear cutting and reforestation, breeding of resistant trees, etc.

Lycorma delicatula (White 1845), which has been recently introduced into Korea, is a notorious pest on grapes. This invasive insect has rapidly spread throughout central and southern Korea. To date, we have no behavioral or population genetics information, such as invasion routes and subsequent dispersal rates in Korea, to help understand and control populations of L. delicatula. Here, we have developed 15 novel microsatellite loci for L. delicatula. The isolated loci were polymorphic, with 2 to 19 alleles in 42 individuals from a single population in Cheonan. The analyses revealed that all 42 individuals had different multilocus genotypes with heterozygosity ranging from 0.214 to 0.866. Eleven of the 15 loci did not deviate significantly from Hardy-Weinberg equilibrium. The isolated markers will facilitate population genetic studies of L. delicatula.

A postharvest treatment called CATTS (controlled atmosphere and temperature treatment system) has been used as an alternative nonchemical measure for methyl bromide fumigant treatment. This study applied CATTS to control the red flour beetle, Tribolium castaneum, infesting stored grains. Adults of T. castaneum were susceptible to 46℃ heat treatment. The susceptibility was further enhanced by addition of CA conditions (15% CO₂ and 1% O₂). When CATTS (46℃, 15% CO₂, 16℃/h treating rate) was applied to different developmental stages of T. castaneum, it showed 100% control efficacy by 120 min exposure. There was a variation in CATTS susceptibility among developmental stages, in which late instar larvae were most tolerant. Heat shock proteins of T. castaneum appeared to be implicated in the tolerance of CATTS.

Neuropeptides are the largest group of neurohormones that act in intercellular communication to regulate various physiological and behavioral events during development and reproduction in animals. One of these families is Pyrokinin/PBAN (Pheromone Biosynthesis Activating Neuropeptide) family defined by a similar 5-amino-acid C-terminal sequence (FXPRLamide) that is the active core fragment for these peptides. This motif has been identified from a variety of insect orders, and even a crustacean species. This family of peptides has been implicated in various physiological functions: 1) moth pheromone biosynthesis, 2) larval melanization, 3) moth embryonic and pupal diapause, 4) visceral muscle contraction in the cockroach, 5) fly puparium formation in different insect species. To date, ~159 PBAN/Pyrokinin family peptides have been identified from 40 species. It is one of the largest neuropeptide families in insects; however, the physiological function of most of these peptides is unknown. The mechanism of PBAN control over pheromone production is only well defined for sex pheromone biosynthesis in a limited number of lepidopteran moths. No other insect groups have been reported to regulate pheromone biosynthesis using PBAN. Conventional insecticides target synapses and/or sodium channels that result in neurotoxicity in the nervous system. Unfortunately, this mode of action affects non-target animals as well. These methods remain the major tool for pest control, and the side effects cause many global problems that result in increased environmental and human health expenses. Therefore, we are faced with a requirement to develop new targeted control agents that will lead to pesticides with new modes of action. This is not impossible, but not easy. Every species-specific neuropeptide is expected to play a critical physiological function in metamorphosis and development of insects. There are no exceptions. Our long-standing question is – “how can interference/disruption ofthe insect (neuro)hormonal system be used to discover novel control tools”. To solve this question a novel approach is being applied for finding and screening novel agonist and/or antagonist to gene products, neuropeptide and receptor, from the in vitro system and through virtual modeling. This concept will be a new paradigm opening the window for the next generation of the pest control, and the principle method will be adapted for insect specific pests. Another research interest here will be presented on exocrinal products, such as semiochemicals produced from insects and plants for chemical communication that regulates insect/insect and insect/host interactions. These studies have included the identification of pheromones and the biosynthetic pathway of their production from insects. The ultimate goal of this research is to discover novel biologically-based green pesticides that are environmental-friendly pest control alternatives.

Monitoring was conducted to investigate the occurrence of Grapholita dimorpha Komai in Korean apple orchards using sex pheromone traps. G. dimorpa showed four peaks per year: early May, from late June to early July, from late July to mid August, and from late August to September. After adult emergence of the over-wintered G. dimorpha, G. dimorpha catches was decreased significantly and increased again after July. In G. molesta traps, G. molesta and G. dimorpha were trapped by 98.8 and 1.2%, respectively. Conversely in G. dimorpha traps, G. dimorpha and G. molesta were trapped by 99.7 and 0.3%, respectively. The 30.6% of the moths from the damaged apple fruits were G. dimorpha. This is the first report on G. dimorpha in apple orchards in Korea.

Major fruit moths in commercial apple orchards are known as Carposina sasakii and Grapholita molesta. In addition, recently G. molesta is dominant species compared with C. sasakii in apple orcahrds. In case of Japan, the fruit damage occurred a lot unexpectedly in apple orchards of the northern Nagano during the harvesting season in 2004. As the result of identifying after emerging the larvae collected from the damaged fruit, Grapholita dimorpha was found out. The morphology of Grapholita dimorpha are almost similar to that of Grapholita molesta, and the shape of the damaged fruits was too similar to distinguish them. We installed sex pheromone traps of Grapholita dimorpha in apple orchards to check if there were Grapholita dimorpha in Korean apple orchards and to survey seasonal occurrence. As a result of survey by installing sex pheromone traps of G. dimorpha at one apple orchard in Uiseong-Gun and Gunwi-Gun area respectively, we could find high population density of G. dimorpha in sex pheromone traps. The peak of the first generation of G. dimorpha was dated in early May. The first generation occurrence of G. molesta in sex pheromone traps was lower than that of Grapholita molesta. However, it had higher occurrence of sex pheromone traps than G. molesta since it increased after mid and late July. Also, as a result of identifying in G. molesta traps, there were 673 G. molesta and 8 G. dimorpha. As a result of survey of 1,102 G. dimorpha in its sex pheromone traps, there were 1,099 G. dimorphaand 3 G. molesta.

Insect occurrence is closed related to crop and environment. Global climate changes as environment factor influencing not only crops but also insects on their behavior, distribution, development, survival and reproduction. Insect life stage are most often calculated using accumulated degree days from base temperature and biofix point. Temperature is also main factor to changes in moisture humidity and CO2 that effect on crop and insect development. Precipitation is another climate change on consideration factor to insect survival. Therefore, the precise impacts of climate change on insects is somewhat uncertain because it may change favor some insects while others may inhibit their development. On predicting the impact of climate change on insect is very complex exercise and need closed cooperation with experts on modeling. Some generalized predictions can be made, based on current pest distributions and severity of insect outbreaks in individual regions. At the present in Thailand, some alien insect species often present by global trades as by climate change.

Road-map for the environmental friendly integrated pest management (IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer’s field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.

Polydnavirus is a mutualistic DNA virus found in some braconid and ichneumonid wasps. Its genome is integrated into host chromosome as a provirus. Its replication occurs at ovarian calyx epithelium during host pupal stage to form episomal viral particles. The viral particles are delivered into hemocoel of the parasitized insect along with eggs during wasp oviposition. Several polydnaviral genomes, which are isolated from the episomal virus particles, have been sequenced and exhibit some gene families with speculative physiological functions. This review presents the viral characteristics in terms of its parasitic physiology. For developing new insect pest control tactics, it also discusses several application strategies exploiting the viral genome to manipulate insect physiology.