Description of pre-adult stages of the coconut bug, Pseudotheraptus wayi

Abstract

The coconut bug, Pseudotheraptus wayi Brown (Hemiptera: Heteroptera: Coreidae), is a serious pest of a number of crops in Eastern and Southern Africa. Both adults and nymphal stages are destructive because they suck sap from their hosts. The identity of the pest is currently based exclusively on the description of adults. This paper describes eggs and instars of P. wayi, with the goal to enhance identification of all stages for effective monitoring and management of the pest. Morphological illustrations are presented, and differences among the instars, as well as their relationship with the adult stage, are discussed.

Figure 1.

A). An egg of Pseudotheraptus wayi deposited on a cashew leaf; length 1.85 ± 0.05 mm, width 1.26 ± 0.02 mm, weight 1.27 ± 0.07 mg; Photo: Fabian Haas; scale bar: 1 mm. B). First instar of P. wayi; weight 1.09 ± 0.05 mg; antennomeres (from proximal to distal) 0.81 ± 0.03 mm, 0.95 ± 0.02 mm, 0.77 ± 0.01 mm, 0.6 ± 0.01 mm; synthlipsis 0.46 ± 0.01 mm; pronotum 0.25 ± 0 mm long, 0.88 ± 0.14 mm wide; Photo: Fabian Haas; scale bar: 2 mm. C). Second instar of P. wayi; weight 3.37 ± 0.64 mg; antennomeres 1.27 ± 0.02 mm, 1.59 ± 0.02 mm, 1.29 ± 0.02 mm, 0.74 ± 0.01 mm; synthlipsis 0.61 ± 0.01 mm; pronotum 0.38 ± .02 mm long, 0.85 ± 0.02 mm wide; Photo: Fabian Haas; scale bar: 1 mm. D). Third instar of P. wayi; weight 6.4 ± 0.22 mg; antennomeres 1.72 ± 0.02 mm, 2.1 I ± 0.02 mm, 1.52 ± 0.53 mm, 0.79 ± 0.09 mm; synthlipsis 0.68 ± 0 mm; pronotum 0.52 ± .01 mm long, 1. 14 ± 0.01 mm wide; Photo: Fabian Haas; scale bar: 1 mm. E). Fourth instar of P. wayi; weight 25.18 ± 2.783 mg; antennomeres 2.21 ± 0.042 mm, 2.67 ± 0.07 mm, 1.81 ± 0.04 mm, 1.41 ± 0.06 mm; synthlipsis 0.8 ± 0.01 mm; pronotum 0.79 ± 0.04 mm long, 1.81 ± 0.04 mm wide; Photo: Fabian Haas; scale bar: 2 mm. F). Fifth instar of P. wayi; weight 47.96 ± 3.52 mg; synthlipsis 0.92 ± 0.02 mm; antennomeres 2.82 ± 0.05 mm, 3.1 2 ± 0.08 mm, 2.12 ± 0.05 mm, 2.17 ± 0.051 mm; pronotum 1.25 ± 0.07 mm long, 3.06 ± 0.03 mm wide; Photo: Fabian Haas; scale bar: 2 mm. G). A couple of P. wayi (♀ on the left) mating on French bean pods used for feeding at the insectary; weight ♀: 54.68 ± 1.87 mg, ♂: 44.02 ± 1.78 mg; antennomeres ♀: 2.79 ± 0.07 mm, 3.21 ± 0.03 mm, 2.1 ± 0.04 mm, 2.32 ± 0.09 mm; ♂: 2.72 ± 0.1 mm, 3.27 ± 0.07 mm, 2.21 ± 0.03 mm, 3.04 ± 0.06 mm; synthlipsis ♀: 1.08 ± 0.04 mm, ♂: 1.04 ± 0.05 mm; length of pronotum ♀: 2.2 ± 0.12 mm, ♂: 2.5 ± 0.06 mm; width of pronotum ♀: 4.19 ± 0.19 mm, ♂: 4.26 ± 0.11 mm; Photo: JP Egonyu; scale bar: 2 mm. H). Side view of a ♀ P. wayi; Photo: Fabian Haas; scale bar: 2 mm. High quality figures are available online.