The consequences of sublethal exposure to insecticide on the survivorship and mobility ofHalyomorpha halys(Hemiptera: Pentatomidae)

Abstract

Many insecticide-exposed H. halys adults retained significant mobility and flight capacity, with flight most pronounced immediately after exposure. These results suggest that brief exposure periods to efficacious insecticides will result in high dispersal and low mortality. Therefore, management strategies that enhance the retention of H. halys on insecticide-coated surfaces should be considered to ensure that adults are exposed to a lethal dose of insecticide. © 2016 Society of Chemical Industry.

Lethal and sublethal effects of long‐lasting insecticide‐treated nets on the invasive bug Halyomorpha halys

“…With regard to the LI, the values calculated in this work for different exposure times were comparable with those obtained in similar studies where different pyrethroids (e.g., bifenthrin) had been employed (Leskey, Lee, et al., ; Leskey, Wright, et al., ; Morrison et al., ).…”

“…Pyrethroids are well‐known neurotoxic chemicals causing the uncoordinated movement of limbs, often followed by a complete loss of mobility without signs of activity and eventual death (Lee, Wright, et al., ; Leskey, Lee, et al., ; Leskey, Wright, et al., ). Nonetheless, the efficacy of α‐cypermethrin as a pesticide had never been investigated against H. halys, although pyrethroids (e.g., cypermethrin, cyhalothrin, cyfluthrin, bifenthrin) are considered among the most effective chemicals, not only against BMSB but also against pentatomids more generally (Lee, Wright, et al., ; Leskey, Lee, et al., ; Leskey, Wright, et al., ; Mooneyham et al., ; Morrison et al., , ; Nielsen et al., ; Willrich et al., ). Even if further specific trials are required to define standard levels of toxicity, our results showed that this compound has a strong insecticidal activity against BMSB.…”

“…Overwintering adults (males and females) of BMSB were collected in January 2017 in two infested sites in northern and Central Italy (44°37.53′18″N–11°01.41′98″E; 43°38′16.16″N–10°02′07.18″E). Individuals were collected gently by hand in farmers facilities (e.g., depots) and then laboratory reared for 3 weeks in insect cages (40 × 40 × 80 cm), located in rearing rooms set at 25 °C and 16:8 L:D, with the aim to break diapause and return them to an active stage (i.e., able to feed, move and fly); dead insects, injured specimens (with no intact limbs and/or antennae) and weakened individuals were removed from cages before starting the tests (Leskey, Agnello, et al., ; Leskey, Lee, et al., ; Morrison et al., ). Insects were provided with green beans, fresh carrots, sunflower seeds and peanuts as food, which was replenished three times per week.…”

“…After exposure, each specimen was gently removed from the arena and introduced into a smaller insect rearing plastic box closed with perforated lids (24 × 18 × 6 cm) and provided with moistened cotton and green beans ad libitum as water and food sources, respectively. The effects of α‐cypermethrin on exposed H. halys adults were monitored daily, and their health condition was categorized as: (i) active (fully able to move, e.g., walking horizontally and vertically; flying attempts are sometimes observed), (ii) paralysed (ranging from a partial functional impairment of legs and/or leg/antennae, to a more advanced stage of paralysis; specimens are often unable to right themselves if flipped upside down or are completely paralysed except for subtle movements of legs or antennae) and (iii) dead (showing complete loss of movement when probed using a fine brush) (Leskey, Lee, et al., ; Leskey, Wright, et al., ; Morrison et al., ). Adults were monitored daily until death or (regardless of whether they had been affected by the insecticide or they simply recovered from paralysis) until they showed no detectable insecticide‐induced effects for at least 5 consecutive days after treatments.…”

“…The lethality index (LI), as reported by Leskey, Lee, et al., (), Leskey, Wright, et al., (), was independently calculated for insect gender and time of exposure using pooled data of dead, paralysed and live specimens. The LI was calculated on day 7 after treatments (Leskey, Lee, et al., ; Leskey, Wright, et al., ; Morrison et al., ).…”