Lekking Behaviour and Male-Male Rivalry in the Melon Fly Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae)

Abstract

Most studies on the sexual behaviour of tephritid fruit flies are conducted in laboratory or field cage settings. Here, we present field data on the mating behaviour of the melon fly, Bactrocera cucurbitae (Coquillett). A number of Tephritidae are lekking species, forming aggregations in which males fight to defend a small territory where they court females and mate. Our results confirm that males of the melon flies congregated and engaged in wing vibration in the late afternoon on non-host plants, such as Ficus carica, Cydonia oblonga and Prunus persica which bordered cucurbit fields. The nature and outcome of male-male aggressive encounters are described, and a high degree of female mate selectivity is documented.

Larval host plant influences male body size and mating success in a tephritid fruit fly

“…Third, the mating advantage of large males may have reflected their dominance in aggressive encounters. Compared to some other tephritid species, and consistent with prior observations (Kuba & Koyama, ; Iwahashi & Majima, ; Mir & Mir, ), encounters between Z . cucurbitae males were not particularly elaborate or intense.…”

“…Third, the mating advantage of large males may have reflected their dominance in aggressive encounters. Compared to some other tephritid species, and consistent with prior observations (Kuba & Koyama, 1985;Iwahashi & Majima, 1986;Mir & Mir, 2016), encounters between Z. cucurbitae males were not particularly elaborate or intense. In the olive fly Dacus oleae (Rossi), for example, aggressive interactions followed a regular sequence of behaviors, and males frequently pounced and head-butted one another in agonistic interactions lasting 15-20 s (Benelli, 2014).…”

“…Mounts were the abrupt jumps onto the top of the other male. Although such mounts may have indicated the inability of males to discern the sex of a nearby conspecific, previous studies (Iwahashi & Majima, 1986;Mir & Mir, 2016) indicate that Z. cucurbitae males can, in fact, distinguish between the sexes (prior to contact) and thus considered male mountings as acts of aggression (see also Lane et al, 2016). Two additional types of aggressive encounters, namely head-butting and wrestling, were also observed, but only rarely, and were therefore not included in the analysis.…”

“…The melon fly, Zeugodacus (previously Bactrocera ; Virgilio et al., ) cucurbitae (Coquillett) (Diptera: Tephritidae), is a world‐wide, agricultural pest that primarily infests plants of the family Cucurbitaceae but also attacks hosts in unrelated families (Dhillon et al., ; Piñero et al., ). The species exhibits a lek mating system, in which males defend individual leaf territories that are spatially aggregated and that contain no resources critical to females (Iwahashi & Majima, ; Mir & Mir, ). Thus, males provide only ejaculate to females.…”

Sexual Selection on Leks: A Fruit Fly Primer

“…Field observations in Japan showed that, despite the presence of a preferred host, males of the melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), aggregated and displayed most frequently on nonhost (and herbaceous) species of Asteraceae ( Iwahashi and Majima 1986 ). Leks of this species were most commonly found on nonhost plants in India as well ( Mir and Mir 2016 ). In the wild tobacco fruit fly, Bactrocera cacuminata (Hering), a field-cage experiment indicated that nonhost plants containing the phenylpropanoid compound methyl eugenol, a known male attractant, serve as rendezvous sites for mating ( Raghu and Clarke 2003 ).…”