The aim of this review is to describe ecological and physiological features of Andrallus spinidens Fabricius and to discuss various possibilities of using it as an appropriate biocontrol agent in different agroecosystems. This hemipteran is a cosmopolitan predator of caterpillar pests of rice, wheat, soybean, moong, pigeon pea, maize, sugarcane and cowpea with special feeding on Chilo suppressalis Walker, Naranga aenescnes Moore, Helicoverpa armigera Hübner and Spodoptera litura Fabricius. Climate, spatial distribution of prey and type of agricultural crop are among the factors influencing the biology and spatial-temporal distribution of A. spinidens. Studies have shown random or aggregated distribution of the predatory bug with population peaks in April, July and October. The 1st instar nymphs have no feeding, the 2nd and 3rd (the first 2 days) instars are seedling feeders while they are voracious predators of caterpillars from the middle of 3rd instar to adulthood. The salivary gland consisted of two anterior-, two lateral- and two posterior lobes with major secretion of trypsin, chymotrypsin, amino- and carboxypeptidases. The alimentary canal has a four-sectioned midgut in which the third section seems to be the main place for digestive enzymes including α-amylase, trypsin, chymotrypsin, elastase cathepsins B, L and D as well as carboxy- and aminopetidases. Andrallus spinidens have shown compatibility with some insecticides and the entomopathogenic fungus, Beauveria bassiana. The predatory bug may be successfully reared in a laboratory using Galleria mellonella larvae as prey and both conservation and augmentation should be considered as biological control strategies against insect pests.

The effects of two native isolates of Beauveria bassiana, AM-118 and BB3, were evaluated on the predatory coccinellid, Cryptolaemus montrouzieri by measuring several developmental parameters and intermediary metabolism. Treatment with both isolates significantly increased the length of each developmental stage compared to the control except for the eggs and adults. The preovipositional period in the adults treated with BB3 significantly increased compared to those treated with AM-118 and the control. Other parameters, including longevity, length of oviposition period and fecundity, showed no significant differences between treatments. Although there were no significant differences in the parameters of net reproduction rate ( R₀) and gross reproduction rate ( GRR) between the control and fungal treated C. montrouzieri, the intrinsic rate of population increase ( r) and finite rate of population (λ) for the control treatments were significantly higher. The activities of both aminotransferases in the larvae and the adults treated with both isolates significantly increased 96 hours post-treatment compared to the control. Although similar results were recorded for acid phosphatase activity, alkaline phosphatase activity showed no significant differences in larvae and adults between the treatments. The amount of protein significantly decreased in the larvae and the adults treated with both isolates after 96 hours, while the amount of triglyceride significantly reduced in the treated larvae compared to control. No significant differences were observed in adults. Our results indicated that both native isolates of B. bassiana may affect life fitness of C. montrouzieri but isolate AM-118 was more compatible than BB3.

Protein digestion in insects relies on several groups of proteases, among which trypsin plays a prominent role. In the current study, larvae of Pieris brassicae L. were fed radish leaves treated with 1 mM concentrations of three specific inhibitors of trypsin: AEBSF.HCl [4-(2- -aminoethyl)-benzenesulfonyl fluoride, monohydrochloride], TLCK (N-a-tosyl-l-lysine chloromethyl ketone) and SBTI (Soybean Trypsin Inhibitor) to find their potential effects on gene expression of trypsin. Initially, RT-PCR analysis revealed a gene of 748 bp responsible for synthesizing the digestive trypsin in P. brassicae larvae. Also, qRT-PCR data indicated a statistically greater expression of trypsin gene in the larvae fed 1 mM concentrations of AEBSF.HCl, TLCK and SBTI than the control. Results of the current study indicated that synthetic inhibitors can not only negatively affect the gene expression of P. brassicae trypsin, but also the insect can activate a compensatory mechanism against interruption of protein digestion by inducing more expression of the gene and producing more trypsin into the midgut lumen.

The green peach aphid, Myzus persicae (Sulzer), is a polyphagous and holocyclic aphid which significantly damages agricultural crops. In the current study, the effects of micronutrients on some secondary metabolites of bell pepper (Capsicum annum L.) leaves and their subsequent influence on the life table parameters of M. persicae were investigated under greenhouse conditions. The flavonoid content in bell pepper leaves significantly changed following micronutrient treatments in the wavelength of 270 nm while there were no significant differences in the wavelengths 300 and 330 nm. The highest anthocyanin content was recorded after Fe treatment (3.811 mg ⋅ ml–1) while the total phenolic content in the bell pepper leaves increased after Mn (541.2 mg ⋅ ml–1) treatment compared to Fe (254.5 mg ⋅ ml–1) and control (216.33 mg ⋅ ml–1), respectively. The highest values of intrinsic (r) and finite rates of population increase (λ) of M. persicae were gained with Zn (0.320 and 1.377 day–1, respectively) treatment although the highest and the lowest values of the mean generation time (T) were found with Fe and Zn (14.07 and 12.63 days, respectively) treatments, respectively. Our findings suggest that Mn, more than Zn micronutrients, decreased ecological fitness of green peach aphid and may help enhance the efficiency of pest control techniques.

Development and demography of Adalia decempunctata L. were studied under laboratory conditions at seven constant temperatures (12, 16, 20, 24, 28, 32 and 36°C). First instar larvae failed to develop to second instar at 12°С and no development occurred at 36°C. The total developmental time varied from 47.92 days at 16°C to 15.94 days at 28°C and increased at 32°C. The lower temperature thresholds of 11.05 and 9.90°C, and thermal constants of 290.84 day-degree and 326.34 day-degree were estimated by traditional and Ikemoto-Takai linear models, respectively. The lower temperature threshold (Tmin) values estimated by Analytis, Briere-1, Briere-2 and Lactin-2 for total immature stages were 11.99, 12.24, 10.30 and 10.8°C, respectively. The estimated fastest developmental temperatures (Tfast) by the Analytis, Briere-1, Briere-2 and Lactin-2 for overall immature stages development of A. decempunctata were 31.5, 31.1, 30.7 and 31.7°C, respectively. Analytis, Briere-1, Briere-2 and Lactin-2 measured the upper temperature threshold (Tmax) at 33.14, 36.65, 32.75 and 32.61°C. The age-stage specific survival rate (sxj) curves clearly depicted the highest and lowest survival rates at 16 and 32°C for males and females. The age-specific fecundity (mx) curves revealed higher fecundity rate when fed A. gossypii at 24 and 28°C. The highest and lowest values of intrinsic rate of increase (r) were observed at 28 and 16°C (0.1945 d–1 and 0.0592 d–1, respectively). Also, the trend of changes in the finite rate of increase (λ) was analogous with intrinsic rate of increase. The longest and shortest mean generation time (T) was observed at 16 and 28°C, respectively and the highest net reproductive rates (R0) was estimated at 24 and 28°C. According to the results, the most suitable temperature seems to be 28°C due to the shortest developmental time, highest survival rate, and highest intrinsic rate of increase.