Mating preferences of two species of Eccritotarsus (Hemiptera: Miridae)

ABSTRACT

Eccritotarsus spp. are biological control agents that have been sourced from Brazil and Peru to control water hyacinth in South Africa. These agents have been released in over 30 sites and were thought to be the same species. The sequencing of mitochondrial DNA and interbreeding experiments have since confirmed the cryptic species to be separate species. The Brazilian population remains E. catarinensis while the Peruvian population is now E. eichhorniae. This paper assessed the mating behaviour of both species, to investigate behavioural traits that have resulted in reproductive isolation, which could have led to speciation. Mating choices in a form of no-choice, bi-choice and multi-choice tests were conducted within and between species in a 3:1, 2:1 and 1:1 sex ratio. The E. eichhorniae pair had more single and multiple copula incidences, higher average total copula duration and higher copula latency while the E.catarinensis♀×E.eichhorniae♂ pair had less single and multiple copula incidences, lower average total copula duration and lower copula latency. When the E.eichhorniae♀ and E.catarinensis♂ were given their respective choices, they only mated with conspecifics. However, when E.eichhorniae♀ are crossed with E.catarinensis♂ they do not produce offspring. These results suggest that interbreeding will be limited in South Africa.

KEYWORDS:

• Eccritotarsus
• biological control agents
• mating behaviour
• Brazil and Peru

Acknowledgements

I would like to thank Miss E. I. T. da Silva for the behavioural markers; people working at the Biological Control Quarantine Facility and Waainek Mass Rearing Facility at Rhodes University for ensuring that I always had insects and plants to conduct my experiments; and my supervisors, Dr I. D. Paterson, Dr L. U. P. Heshula and Prof J. A. Coetzee for their guidance.

Disclosure statement

No potential conflict of interest was reported by the author.

ORCID

S. Mnguni http://orcid.org/0000-0002-3077-2162

Additional information

Funding

I have received a Scarce Skills Masters Scholarship from National Research Foundation (Grant UID: 95616). I have also received a grant holder-linked Rhodes University Research Development Grant and the Department of Environmental Affairs Working For Water (DEA WFW). I am currently funded by DST-NRF Innovation Doctoral Scholarship (Grant UID: 113518), Palaentological Scientific Trust (PAST) and DST-NRF Centre of Excellence in Palaeosciences Top-Up (Reference: COE2018-16PHD).