The survival and development of strain C of Scirtothrips dorsalis Hood（Thysanoptera: Thripidae）reared on the leaves of Capsicum annuum, were studied at temperatures ranging from −5°C to 35°C, and the abundance of thrips of strain C living on strawberry（Fragaria×ananassa Duch.）plant bodies were investigated under outdoor conditions in Kochi Prefecture, Japan, from October to April 2013–14 and 2014–15. A positive linear relationship was observed between the development rate from egg to adult and temperature in the range of 17.5°C to 32.5°C, allowing the calculation of a lower threshold of 12.4°C for development and a thermal constant of 200.0 degree-days（DD）. An exposure time of nearly 3.5 days at 0°C and nearly 2.5 days at −5°C killed 50% of the adults. In contrast, over half of the 2nd instar larvae survived for more than 5.5 days at 0°C and more than 3 days at −5°C, while approximately 20% of the larvae exposed to −5°C for 3 days emerged as adults at 25°C. In the field experiment, both adults and larvae disappeared from the strawberry plants by the end of February 2014 and 2015, with no individuals being found from March onward in either year. These findings suggest that strain C of S. dorsalis is unlikely to survive for the duration of a mild winter under outdoor conditions in Kochi Prefecture, but individuals could survive for a few days, even at temperatures below −5°C.
Euseius sojaensis（Ehara）（Acari: Phytoseiidae）is an effective indigenous natural enemy of Aculops pelekassi（Keifer）（Acari: Eriophyidae）. However, dithiocarbamates, which are seriously harmful to E. sojaensis, are usually applied in commercial citrus orchards in June when the density of this phytoseiid mite peaks. In this study, we examined the suppressive effect of the E. sojaensis release on A. pelekassi in conservation control by using selective pesticides until late June. In the E. sojaensis release plot, phytoseiid populations were larger, A. pelekassi populations were smaller, and the rate of fruit injury was lower than those in the no-release plot; these differences were significant in some years. Many phytoseiid mites were observed in conservation-control orchards, with E. sojaensis being the dominant species; however, only a few phytoseiids occurred in conventional-control orchards. These results suggest that E. sojaensis was conserved by using selective pesticides and the initial density of A. pelekassi was reduced by this phytoseiid mite. However, it is difficult to control fruit injury only by conserving E. sojaensis, because it generally disappears after July. Therefore, we should study the possibilities for enhancement of E. sojaensis populations from summer onwards for sustainable biological control of A. pelekassi.
The toxicity of 29 fungicides was tested against 4 native phytoseiid species, namely, Amblyseius eharai Amitai and Swirski, Amblyseius tsugawai Ehara, Euseius sojaensis（Ehara）, and Typhlodromus vulgaris Ehara（Acari: Phytoseiidae）, which are abundantly found in fruit tree orchards in Japan. Mancozeb and propineb were toxic to the immature individuals of all 4 species and to the fecundity of adult females of E. sojaensis and A. eharai. Thiuram was harmless or slightly toxic to A. eharai, A. tsugawai, and T. vulgaris, whereas it was toxic to E. sojaensis. Sulphur and polyoxin were toxic to the immature individuals of all four species. Benomyl and thiophanate-methyl reduced the fecundity of A. eharai, A. tsugawai, and E. sojaensis. Fluazinam was toxic to immature individuals and the fecundity of adult females of E. sojaensis and moderately toxic to A. eharai and A. tsugawai. Iminoctadine triacetate was toxic to immature individuals of E. sojaensis. Fluoroimide was also moderately toxic to immature individuals of E. sojaensis. On the other hand, basic copper sulfate, oxine-copper, captan, chlorothalonil, iminoctadine tris（albesilate）, dithianon, difenoconazole, hexaconazole, imibenconazole, tebuconazole, fluopyram, inpyrfluxam, isopyrazam, penthiopyrad, pyraziflumid, cyprodinil, kresoxim-methyl, pyribencarb, and trifloxystrobin were harmless to all 4 species.
The solanum mealybug, Phenacoccus solani Ferris（Hemiptera: Pseudococcidae）, has become a serious pest with the extension of the IPM system based on biological control using natural enemies. We tested the efficacy of available insecticides in the laboratory and eggplant fields. Laboratory experiments were performed under a controlled environment of 25°C and 14L:10D using green bean leaflets. To distinguish each developmental stage of P. solani, the body length and developmental time were investigated every day. We were unable to distinguish the different developmental stages of the mealybugs by body length; however, we could estimate the developmental stage from the number of days from birth（day-age）. The estimated developmental stages in terms of day-age were below 4 days for 1st instar nymphs, 8–9 days for 2nd instar nymphs, 14–16 days for 3rd instar nymphs, and over 25 days for female adults. Fourteen insecticides were tested against 2nd and 3rd instar nymphs and female adults. Three chemical insecticides（acetamiprid, nitenpyram, and sulfoxaflor）and two spiracle-blocking insecticides（decanoyloctanoylglycerol and hydrogenated starch hydrolysate（HSH））were particularly effective. The efficacy of selected insecticides（acetamiprid, sulfoxaflor, and HSH）was also evaluated in a greenhouse. The results showed that sulfoxaflor was the most effective, with acetamiprid in second place, and HSH in third.
The sap beetle Phenolia（Lasiodites）picta（MacLeay）（Coleoptera: Nitidulidae）is widely distributed in Asia, Australia, and Africa, but its basic biology has not been studied. In the present study, the seasonal prevalence of P.（L.）picta was investigated using banana bait traps in two regions, Minabe and Arida, Wakayama Prefecture, Japan, from April to October 2015 and 2016. Adults of P.（L.）picta occurred from late April–late October in Minabe, and late April–early September in Arida, respectively. The presence of larvae was observed twice in May–July and August–October in Minabe, but only once in May–July in Arida. These results imply that P.（L.）picta is a bivoltine in Minabe. The beetles oviposit in leaf mold, and a successful artificial rearing method was established using banana fruit and leaf mold. The effects of long and short photoperiods（long photoperiod, 14.5L:9.5D; short photoperiod, 10L:14D）on the ovarian development of females during ‘larval and pupal’ and ‘adult’ stages, respectively, were also studied in the laboratory. Females reared with a long photoperiod across all stages had significantly higher percentages of ovarian development（77.3%）than those reared with a short photoperiod during either ‘larval and pupal’ stages（20.0%）or ‘adult’ stages（35.0%）.