From: Modelling sterile insect technique to control the population of Anopheles gambiae
Biological observation | Model notes | |
---|---|---|
[38] Foster et al. 1988 | Modelled EBS and female-killing of a | Computational model that works on |
hypothetical insect population at various | discrete generations comparing each male | |
migrations, release rates, incomplete sterilities, | genotype with each female genotype. | |
and number of mutated alleles. Under most, | ||
but not all scenarios, EBS achieves better | ||
control than female-killing. | ||
[39] Schliekelman and Gould 2000a | The authors model a hypothetical transgenic | The model uses combinatorics to determine |
implementation in hypothetical insects | a population’s genetic make-up as inherited | |
whereby there are multiple lethal genes | from parents. Lethality is operational in a | |
in released insects and these lethal genes | population subset with the correct allele | |
are conditional, killing only when certain | active in their genotype. | |
conditions are met and otherwise propagate. Found that under ideal conditions, this | ||
implementation can be far more effective | ||
than traditional EBS. | ||
[40] Schliekelman and Gould 2000b | Modelled transgenic implementation whereby | This model maintains 20 population signals, |
2–20 lethal genes were engineered into a | one for each possible active allele. | |
hypothetical insect. As the number of lethal | Inheritance is captured as generations | |
genes per released animal increases, there is a | inherit their genetic makeup from the | |
greater chance any one progeny will inherit a | previous generation. | |
lethal gene. Found under ideal conditions, | ||
control could be achieved at rates several | ||
orders of magnitude more effectively than | ||
single gene EBS. | ||
[41] Barclay 2001 | Modelled EBS in hypothetical insects, with | The analysis is performed with a discrete- |
special regard to incomplete sterility and lack | time population model. The paper reports | |
of competitive mating ability, which cause | on many factors including equilibrium | |
decreased levels of control success. | female population with regards to | |
incomplete fertility. | ||
[42] Esteva and Yang 2005 | Models EBS implementation in males | Equation-based population model with |
engineered to have no sperm. Release | density dependent mortality. | |
proportion is important. | ||
[22] Phuc et al. 2007 | Compared EBS to LBS. They found that EBS at | Time-delayed difference equation model |
low release ratios can increase equilibrium size | with a density-dependent mortality in the | |
of adult population, but LBS can result in | aquatic life-stage and based on [43]. The | |
eradication. At high release ratio EBS works but | difference between EBS and LBS was | |
LBS works better. | characterized in population suppression. | |
[44] Kean et al. 2008 | Frequent small releases of EBS moths may be | Discrete-time population model with |
more effective than less frequent releases. They | overlapping generations. This model takes | |
also compared how competitiveness of | into account an over flooding parameter | |
irradiated males effected control. Models doses | and incomplete sterility. | |
of radiation which result in reduced, but not | ||
complete sterilisation of males to the benefit of | ||
increased mating competitiveness. | ||
[45] Yakob et al. 2009 | Modelled LBS, EBS, EFK, and LFK of a | Time-delayed difference equation model |
hypothetical insect population at various | representing the mosquito’s lifecycle with | |
release proportions, migrations, density | adult and larval mortality terms. | |
dependancies, and fecundities. Found bisex | ||
lethal could be preferred over female killing | ||
under certain scenarios. | ||
[46] White et al. 2010 | Models Ae. aegypti, EBS and LBS releases. Found | Population dynamics are modelled with |
control is more effective with fewer males | a time-delayed difference equation model | |
released more often than many males released | extended from [43]. EBS and LBS are | |
less frequently. | modelled and the dynamics of injected pulses of mosquitoes are reported. | |
[47] Deredec et al. 2011 | Models an An. gambiae EFK implementation | This work extends a population model |
where the X chromosome in sperm is targeted | by adding HEG dynamics and focuses on | |
(and two other transgenic techniques that are | reducing the intrinsic reproductive rate of | |
outside the scope of this paper) by release | the female population. Density dependent | |
of mosquitoes carrying homing endonuclease | mortality is considered for larvae. | |
genes (HEG). Determined the number of | ||
individual HEGs targeting essential mosquito | ||
genes required at various mosquito | ||
reproductive numbers with various homing | ||
rates to eliminate a mosquito population. | ||
[37] Thailayil et al. 2011 | Models release size of spermless An. gambiae | Differential equation model with no explicit |
(EBS) males required at differing rates of | time latency between generations. The | |
occurrences where females mate more than | adult female population separated into | |
once. Very low levels of remating events were | females who have not mated; mated and | |
found to have significant negative effects on | fertile; mated; and infertile. Population | |
the ability to control the mosquito population. | persistence was described in terms of the model coefficients. | |
[48] Dumont and Tchuenche 2011 | Found it more effective to have small and | Extensive system of equations which |
frequent releases of EBS males over large | captures population and compartmental | |
infrequent releases. Also EBS works better | dynamics. | |
when carried out with a larval habitat control | ||
program (mechanical control). | ||
[49] Lee et al. 2013 | Modelled EBS & LBS in Ae. aegypti mosquitoes | Difference equation model similar to [22] |
under endemic and emerging outbreak | but look at an endemic case and emerging | |
scenarios. Evaluated various release and | outbreak of mosquito populations. | |
intervention-region sizes. Found EBS was | ||
always more effective than EBS, though the the | ||
magnitude varied by situation. |