The influence of intraguild competitors on reproductive decisions by two predatory Heteroptera,Orius insidiosus(Anthocoridae) andNabis americoferus(Nabidae)

Abstract

The relationship between the oviposition site preferences of predators in the face of intraguild competitors has received little attention, but it likely shapes the reproductive ecology of predatory species. In this study, oviposition intensity and the within-plant distribution of Orius insidiosus (Heteroptera: Anthocoridae) and Nabis americoferus (Heteroptera: Nabidae) eggs on Phaseolus vulgaris plants was studied when the two species were present independently or in combination. Both predators laid more eggs in the presence of the other species relative to when they were only exposed to conspecifics. When only exposed to conspecifics, O. insidiosus preferred to lay eggs on leaves and petioles on the upper half of the plant, whereas N. americoferus laid eggs mostly on the petioles and petiolules equally throughout the height of the plant. But when both species were present, O. insidiosus preferred to lay eggs on the leaf, whereas N. americoferus altered their behavior to lay an even greater proportion of their eggs on the petioles and petiolules. They altered their preferences for different plant strata too: N. americoferus laid more eggs on the upper quarter of the plant when O. insidiosus was present, and O. insidiosus was marginally more likely to lay eggs lower on the plant in the presence of N. americoferus. This study indicates that these two Cimicomorpha can detect the presence of one another, and that they adjust their reproductive decisions, presumably to avoid potential competitive interactions.

Do Development and Diet Determine the Degree of Cannibalism in Insects? To Eat or Not to Eat Conspecifics

“…This could explain the location of individuals within the plant. In the absence of other predatory species, the females lay eggs mostly into the leaf petioles spread out equally over the height of the plant [104]. Moreover, Nabis adults prefer to sit on the top or slightly lower in the plant canopy, while immature individuals are found lower down in the plant [71,72].…”

The Potential of Nabis americoferus and Orius insidiosus as Biological Control Agents of Lygus lineolaris in Strawberry Fields

“…In eastern Canada, the common damsel bug, Nabis americoferus (Carayon) (Hemiptera: Nabidae), and the minute pirate bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), have been regularly found preying on TPB (F. Dumont, personal observation). Moreover, Pumariño et al (2011) reported that females of both predators laid more eggs in the presence of their competitor than in the presence of conspecifics [18]. Therefore, releasing both predators in a biological control program may increase the numerical reproductive response and consequently the overall impact on the TPB.…”

“…Therefore, releasing both predators in a biological control program may increase the numerical reproductive response and consequently the overall impact on the TPB. The same authors suggested that the simultaneous use of an ambush predator, such as N. americoferus, and an active-searching predator, such as O. insidiosus, may generate a facilitation effect [18]. Yet, the action of the active-searching predator would increase the focal prey movement and then increase the encounter opportunity with the ambush predator [19].…”

Predatory mites protect own eggs against predators

“…Because juveniles and eggs are usually more vulnerable to predation than adults, IG‐prey mothers are expected to select oviposition sites with lower risk of IG predation to increase the survival of their offspring (Almohamad et al, 2010; Choh et al, 2010; van der Hammen et al, 2010; Walzer & Schausberger, 2011). However, IG predators may have a similar preference for oviposition sites as IG prey (Pumariño et al, 2011; Huang & Pike, 2012; Choh et al, 2015; Saitoh & Choh, 2018a). Our recent study showed that IG‐prey mothers protected their eggs against IG predators sharing the same oviposition sites (Saitoh & Choh, 2018a).…”